EAT LESS...

Sugar substitutes Although they curb calories, those pink, blue, and yellow packets can make your stomach swell. “Some people have difficulty digesting artificial sweeteners, such as sorbitol and xylitol,” says Greaves. “That can cause bloating and diarrhea.” Try weaning yourself off them by using a small amount of real sugar. (One teaspoon has 16 calories.)

Canned soup Many boxed, canned, and frozen processed foods are stealthy sources of sodium. A cup of chicken noodle, for instance, can pack in more than a third of your 2,400-milligram daily limit. “Even a small amount of excess sodium can cause your body to retain water,” says Greaves, who recommends choosing low-sodium soups.

Partially hydrogenated oil Researchers from Wake Forest University found that eating a diet high in trans fats may actually cause fat in the body to redistribute itself to the belly. Because “trans fat– free” foods can contain up to 0.5 grams of the stuff per serving, scan ingredient lists on packages.